London Mayor Boris Johnson is considering a plan to charge owners of many diesel cars a supplementary £10 to drive into central London on top of the existing Congestion Charge, pushing the price past the £20 mark to visit the capital.

According to a report by The Times, the Mayor will tonight announce his plans as part of a push to slash air pollution in the capital.

Other cities across the UK could follow by introducing their own versions of London's Low Emissions Zone (LEZ) to meet increasingly stringent clean air rules set by the European Commission.

Under the Mayor's plan – which could be introduced in 2020 – the Euro 6 compliant diesel engines that are currently being rolled out would be exempt from the extra charge, but some older and less-efficient petrol-fuelled cars could be penalised.

London is under severe pressure from Europe policy-makers due to its above-average levels of air pollution, and the toxins produced by diesel vehicles are cited as a key contributor to respiratory diseases. The Congestion Charge currently costs £11.50 per day for vehicles which produce more than 75g/km of CO2.

Mayor Johnson, the newspaper reports, also intends to lobby the government to increase road tax on diesel cars in an effort to persuade motorists to move across to cleaner car models.

Just under half of the new cars registered in the UK each month are diesel-fuelled, according to data from the Society of Motor Manufacturers and Traders (SMMT).

Join the debate

I would support this move. Diesel is a significantly more dirty and carcinogenic fuel vs. petrol but unfortunately, the obsession with CO2 has meant that this has been overlooked with negative outcomes on human health. When driving behind an older diesel it is apparent just how bad the fumes are.

...in an effort to reduce CO2 levels and increase the air quality in central
London - will be next! Have a word Boris. And what about talking fast an farting, surely there's a case there too. Coming to a 2019 copy of exchange and mart near you, thousands of unwanted black cabs and red buses.

About time. The obsession with CO2, and the tax rates of petrol and diesel cars that has resulted has put far too many diesels on our roads. And however clean their exhaust might be when new, Diesels dont have to be that old to start chucking out nasty stuff. What we really need a change to is the CoCar tax rates to stop diesel being the default choice for almost all company car drivers.

While I don't agree with Boris' plans this more than anything highlights the fact that it is the toxins and particulates of diesels that are harmful, yet the government are only obsessed with CO2 and it's impact on the climate change and focus road tax on that. Yet they're so blind to the fact that a low-emitting CO2 diesel coughs up chemicals and polluting elements that are harmful to the environment and us, yet we're being forced to drive more diesels purely because of the extortionate cost of road tax for an equivalent petrol powered car. Even though petrol is a cleaner fuel.

I do understand that diesel cars emit harmful toxins - any observant person can see and smell diesel cars spewing these on our roads, but that was always the case. Why were the diesel cars given preference over petrol cars in the first place? Before the congestion charge limit was 75g/km, most of the cars that could roam free of charge and spit harmful toxins in our beloved London were diesel cars. What a criminal oversight?